Latching mechanism

ABSTRACT

A latching mechanism is provided, such mechanism having a slide held in latched position by a cam received in a recess in the slide, the cam in turn being retained in holding position by a release latch. Upon application of a low magnitude force to the release latch, the cam displaces from its holding position into either the slide recess or the space which the release latch vacated upon movement thereof to unlatch the slide and allow it to slidably move to an unlatched position and perform a specified function.

United States Patent Milanowski et al.

LATCHING MECHANISM Floyd J. Milanowski, Pocomoke City, Md.; Arthur J.Bowman, Jr., Succasunna, NJ.

Inventors:

Assignee: The United States of America as represented by the Secretaryof the Army Jan. 25, 1971 Filed:

Appl. N0.:

US. Cl. .....74/2, 102/76 R Int. Cl. ..G05g 17/00 Field of Search..74/2; 102/76, 78, 79

References Cited UNITED STATES PATENTS 4/1961 Haessler ..74/2

[ 1 May 16,1972

Primary ExaminerMilton Kaufman Attorney-Harry M. Saragovitz, Edward J.Kelly, Herbert Bet] and A. Victor Erkkila [5 7] ABSTRACT A latchingmechanism is provided, such mechanism having a slide held in latchedposition by a cam received in a recess in the slide, the cam in turnbeing retained in holding position by a release latch. Upon applicationof a low magnitude force to the release latch, the cam displaces fromits holding position into either the slide recess or the space which therelease latch vacated upon movement thereof to unlatch the slide andallow it to slidably move to an unlatched position and perform aspecified function.

12 Claims, 6 Drawing Figures PATENTED I W 3,662,607

SHEET 2 OF 3 a; as 84 e7 91 4 INVENTORS,

FLOYD J. MILANOWSKI ARTHUR J. BOWMAN Jr.

PATENTEDIAHB ma 3,662,607

SHEET 3 UF 3 I g W 'H .3 3;

I34 '62 I52 k mm.

\ F INVENTORS,

\ I I 7 FLOYD J. MILANOWSKI ARTHUR J. BOWMAN J:

LATCI-IING MECHANISM The invention described herein may be manufactured,used and licensed by or for the Government for governmental purposeswithout the payment to us of any royalties thereon.

BACKGROUND OF THE INVENTION Various types of releasing devices or latchmechanisms are known which function such that upon application of aforce to a component of the mechanism, another component is released orunlatched to perform a specified function. Such a mechanism, forexample, can be a latching device in which a slide is held restrained ina latched position by a latching member, so that upon release of thelatching member, the slide moves to an unlatched position for performinga specified function. One application involving the use of such types ofrelease or latch mechanisms is in large caliber artillery projectileswherein they can be employed in various ways, e.g., to arm theprojectile following firing. Thus, the movable component or slide mightbe used to unobstruct a firing course in the projectile which prior tofiring was blocked as a safety measure to preclude accidental ignitionof the bursting charge.

Such release mechanisms as are known in the art, particularly asemployed in artillery projectiles have certain disadvantages. Forexample, dash-pot devices commonly have been employed in the manner andfor the purposes mentioned before. Such dash-pot devices, however, aredifficult to maintain and since they utilize hydraulic fluid in theiroperation, present a problem respecting possible fluid leakage which canprevent proper operation of the dash-pot rendering the projectileunsuited for its intended purpose. Other known forms of release or latchmechanisms are generally complicated in construction, have numerousparts and are expensive to make and assemble and maintain.

The present invention overcomes the shortcomings of prior art release orlatch mechanisms, particularly as such mechanisms are known for use inartillery projectiles.

SUMMARY OF THE PRESENT INVENTION The release mechanism of the presentinvention is a device which functions responsive to the application of aforce of low magnitude to a latching component thereof to release underrelatively high energy load, a movable component or slide from a latchedposition to permit the movable component to perform a specifiedfunction.

The release mechanism of the present invention can be used for any oneof a number of purposes heretofore provided by latching mechanisms andis particularly suited for use in an artillery projectile for thepurpose of arming the projectile following firing of the latter. In oneform, the release mechanism includes a housing having a passage thereinin which is received a sliding component, such sliding component havingan enlarged recess formed therein. The housing also includes a secondpassage in which is slidably received a release latch, the release latchbeing employed normally to maintain a movable cam engaged in the recessof the movable component to hold the latter in a latched position inopposition to the biasing force of a spring which functions to slide thecomponent away from its latched position. The release latch ismaintained in its cam-holding or latching position by means of a toggledevice. Upon application of a low energy force to the release latchwhich would slide it away from its latching position, the cam is freedto fulcrum against a fulcrumming surface within the housing and is movedout of the recess in the movable component thereby permitting themovable component to slide from its latched position to a secondposition, during the course of which movement the movable componentperforms a specified function. In such form of the mechanism, the cam isdesigned to retract from the recess of the movable component and locatefully within the release latch passage upon unlatching of the mechanism.When used in an artillery projectile, the release or latch mechanism canbe operated by using the centrifugal force of the rapidly rotatingprojectile as the means for applying a low magnitude force to therelease latch to slide it from its latching position. The movablecomponent or slide during the course of its movement from a latched toan unlatched position can be employed to pivot a blocking lever awayfrom blocking position across a passage in a firing tube within theprojectile and thus arm the projectile.

A modified form of the mechanism provides that the cam upon movement ofthe release latch, retracts fully into the recess of the movablecomponent.

When used in artillery projectile and for providing proper balance ofthe projectile during the course of its post-firing flight, themechanism can be provided pairs of movable components or slides andassociated elements arranged symmetrically of the axis of the projectilewith control or unlatching of the slides being achieved with a singlerelease latch.

The invention accordingly comprises the release or latch mechanismpossessing the features, properties and relation of elements which willbe exemplified in the devices hereinafter described and the scope of thepresent invention will be indicated in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS The invention and a fullerunderstanding of its nature and objects will appear more clearly fromthe following detailed description taken in conjunction with theaccompanying drawings shown by way of example preferred embodiments ofthe inventive concept and in which:

FIG. 1 is a plan view of a release or latch mechanism constructed inaccordance with the principles of the present invention, the movablecomponent or slide thereof being shown in latched position, a portion ofthe housing being broken away to illustrate the structural componentstherein.

FIG. 2 is a plan view similar to FIG. 1 showing the moved or unlatchedposition of the movable component or slide following unlatching thereof,and the manner in which it functions to pivot a blocking lever away froma firing passage in an artillery projectile to arm the latter.

FIG. 3 is a sectional view depicting a modification of the device shownin FIGS. 1 and 2 as it is embodied in an artillery projectile whereinfor purposes of balance, the device is provided with movable componentsand earns arranged symmetrically at each side of the projectile axis.

FIG. 4 shows the unlatched condition of the mechanism depicted in FIG.3.

FIG. 5 is a plan view of a release mechanism similar to that shown inFIGS. I and 2 but modified to the extent that upon unlatching, the cammoves into the recess in the movable component or slide and is carriedalong therewith during its travel from latched to unlatched position,the slide being shown in latched position.

FIG. 6 is the same as FIG. 5 except it shows the slide in unlatchedposition.

Throughout the following description, like reference numerals are usedto denote like parts in the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The release or latch mechanismof the present invention can be made in various embodiments as will bedescribed later, it being understood however that the samelatching-unlatching principles are used in the various forms of themechanism. In the following description, the use of expressions such astop," bottom," left side," right side, etc. are employed as terms ofconvenience in describing the various elements of the mechanism. Theyshould not be understood as implying any limitation as to the physicalpositioning of the mechanism in use.

Referring now to form of mechanism 10 depicted in FIGS. 1 and 2, itincludes an elongated housing comprised of a cover plate 12 superposedon and coextensive with a casting 14, the lower or bottom side of thecasting being provided with a removable stop plate 16, the stop plate 16and cover plate 12 being fastened to the casting 14 by means of machinescrews 17. The casting 14 is provided with a number of speciallyshapedsegments including a segment 18 at the left end and extending from topto bottom of the housing, a segment 20 at the other or right end at thebottom of the housing adjacent the plate 16 and a segment 22 at the topof the housing or the side thereof remote from the stop plate, suchsegments being arranged as will appear to define and provide within thehousing certain passages and cavities. Thus, the segments 18 and 20 areprovided with flat parallel spaced edge faces 24, 26 respectively, whichare arranged such as to define a first passage 28 disposed transverselyof the housing and in which can be received for sliding travel therein,an elongated slide 30. Slide 30 is provided with a relatively deeprecess 32 extending laterally inwardly from a side thereof as shown inwhich can be received one end of a cam 34 received loosely in thehousing, the recess 32 having a flat bottom 301 disposed perpendicularto the faces of the slide. Similarly, segments 20 and 22 are providedwith parallel arranged straight edges 37 and 38 respectively arrangedsuch as to define a second passage 40 in the casting in which can beslidably received a release latch 42, the passage 40 being disposed inthe casting so as at a left end section thereof of reduced dimension tointersect and communicate with the passage 28, the arrangement beingsuch as passage 40 is disposed longitudinally of the housing andsubstantially perpendicular to passage 28. As will be noted in FIG. 1,the recess 32 in the slide with the latter in the latched position,registers with passage 40.

Segment 20 of the casting is provided with an enlarged open portion orcavity 49 wherein is received for pivoting movement therein, a toggleassembly 46, the toggle assembly being employed to apply a certainbiasing to the release latch to normally maintain the latch 42 in eithera latching or non-latching position as shown in FIGS. 1 and 2respectively. The toggle assembly 46 includes complementallongitudinally arranged, slidably longitudinally overlappingly engagedpin elements 48 and 50, the respective pin elements being provided withflanges 52 between which extends a compression spring 54 and theassembly of its opposite ends being engaged with segment 20 and releaselatch 42 respectively. The spring 54 tends to slide the pin elements 48and 50 axially in opposite directions thereby maintaining the oppositerounded ends of the toggle assembly in firm engagement with the roundedrecesses 56 and 58 in the casting segment 20 and release latch 42respectively.

Slide 30 which is coextensive with and fully retracted in passage 28when in a latched position (FIG. 1) is provided with a blind bore 31 inwhich is received a compression spring 33, the compression springengaging against the inner surface of stop plate 16 and acting to urgethe slide upwardly away from the stop plate and outwardly of thehousing. With the mechanism in latched condition, one end, i.e., theleft end of cam 34 in its held position is received in the recess 32 ofthe slide, the cam having one straight longitudinal side edge 62 inabutment with complemental straight portion 301 of recess 32. The otherend of the cam straight side edge 62 is supported on the flat uppersurface 72 of a tongue extension 70 formed at the left end of therelease latch 42. The other longitudinal side edge 64 of cam 34 also isrounded taperingly toward side edge 62 in the direction of the left endand serves to facilitate retraction of the cam from the slide recess aswill be described later. One side of the slide recess 32 is roundedadjacent its entrance as at so that such rounded portion functionsengage the straight side edge of cam 34 with unlatching of slide 30 toinitiate ejection of the cam 34 from the recess 32 by fulcruming itagainst the fulcruming surface to be described next. Casting setment 20is provided with a convexly rounded surface 60, which surface curvesoutwardly relatively of the entrance of the recess 32 in the slide 30 sothat such surface provides a fulcruming surface against which the cam 34can pivot as well as clearance to enable cam 34 to retract from recess32 and outwardly therefrom into passage during unlatching of themechanism.

When the mechanism is in latched condition, slide 30 is fully retractedwithin the housing 10 as shown in FIG. 1. The slide is held in thatcondition by reason of the engagement of the cam 34 at one end in recess32 in the manner depicted in FIG. 1, the cam in turn being held inretaining position by release latch 42 and more particularly theengagement of flat surface 72 of release latch extension 70 with theright or other end of the cam 34. The release latch 42 in turn is heldin its latching position by means of toggle assembly 46 which exerts abiasing force against the release latch to hold it in the extremeleft-hand position shown in FIG. 1. When a pulling force of relativelysmall magnitude is applied to release latch 42 so as to slide it fromleft to right, such force, e.g., centrifugal force if the mechanism isembodied in a rapidly spinning body such as projectile, will slide therelease latch to the right and the toggle assembly will pivot clockwiseabout groove 56. When the pulling force has displaced the release latch42 a sufiicient distance to bring the toggle assembly past its point ofno return, the toggle assembly will now function to bias the releaselatch completely to the right hand position shown in FIG. 2. At aboutthe time the toggle assembly has reached its point of no return, theextension part 70 of the release latch will move out from under theright hand end of cam 34 freeing the cam from the restraint which heldit in static position. The cam now being free to move, starts to pivotin a clockwise direction under the impetus of the upwardly moving slide30 under the influence of compression spring 33. As soon as the slidestarts to move upwardly, the rounded recess edge 35 will engage thestraight edge lower surface 62 of the cam to effect fulcruming of thecam against rounded surface 60. Continued upward travel of slide 30exerts a force against the cam to displace the latter rightwardlycompletely out of the recess 32 and with sufficient magnitude todisplace the cam into passage 40, the rounded other longitudinal sideedge 64 of the cam slidingly abutting with segment edge 38 during suchmovement. With the cam freed from the slide recess 32, the slide willcontinue its sliding travel to its second or unlatched position shown inFTG. 2.

The latching mechanism 10 depicted in FIGS. 1 and 2 can be used forvarious purposes wherein upon moving from a latched to unlatchedposition, a slide is intended to form a specified function. One suchfunction could be the arming of a projectile following firing of same.As shown in FIG. 2 such arming could involve pivoting a blocking lever200 out of blocking position in front of a firing passage 204 in theprojectile body 202. With the mechanism in latched condition beforefiring of the projectile, the blocking lever 200 will occupy theposition shown in short and long dashed lines in FIG. 2, and for thatpurpose suitable spring means or other biasing means (not shown) couldbe employed to maintain the lever in blocking position. Followingfiring, centrifugal force acting on the rapidly rotating projectile canbe utilized to apply a force F of small magnitude on release latch 42 toslide it from left to right and to thereby release the cam 34 from theslide 30. When the slide moves from its latched to unlatched position asshown in FIG. 2, such movement can be employed to pivot the blockinglever 200 to the position shown in solid lines to uncover the firingpassage 204 and thereby arm the projectile.

The latch mechanism of the present invention, as mentioned, can beemployed in an artillery projectile. For such use however it isdesirable that the mechanism be compatible with maintenance of stabilityof the projectile during its flight following firing and particularlywith respect to distributing the weight of the mechanism symmetricallyabout the axis of the projectile. For this purpose the mechanismdepicted in FIGS. 3 and 4 is provided, the construction being such thata pair of slides 81,8 la are used and are disposed symmetrically one ateach side of the projectile longitudinal axis XX. The mechanism iscontained within a housing 89, and includes cams 83, 83a associated withthe respective slides 81, 81a and being received in recesses 82,811formed in the slides in the same manner as described earlier. The slidesare retained in latched condition by the cams and a latching piston 84,the

piston having a section of reduced diameter 85 at the face end thereofwhich engage the cams when the piston is in full lefthand latchingposition. The piston is maintained in latching position by means of astopper or release pin 90 maintained in the left-hand position shown inFIG. 3 and connected with a flange 91 fixed on piston rod 87. A spring86 in compressed position encircles the piston rod and acts to hold thepiston 84 in its latching position. On release of release pin 90, pistonrod 87 will be moved rightwardly by the action of compression spring 86until flange 91 abuts surface 93, at which point spring 86 retains justsufficient compression to hold piston 84 in its latching position. Uponimpact, a force of inertia F causes latching piston 84 to compressspring 86 and to move from left to right from the position shown in FIG.3 to that shown in FIG. 4. Thereby the restraint against movement ofcams 83, 83a applied by piston 84 is released and slides 81, 81a becomeunlatched and slide outwardly of the housing 89 to perform a specifiedfunction. The movement of the slides 81, 81a when they are unlatched isprovided by springs (not shown) in the same manner as described earlierin connection with mechanism 10.

The latch mechanism 110 shown in FIGS. 5 and 6 is modified somewhat fromthat shown in FIGS. 1 and 2 with respect to the plan profile shape ofthe cam 134 and the construction of the segments 122 and 120 as comparedwith the corresponding segments used in the mechanism 10. Moreover, thelatch mechanism 110 functions such that upon unlatching of the slide130, the cam 134 retracts into the recess 132 of the slide to clear itfrom its latching position whereas in the latch mechanism 10, the cam isreceived in the latching lever passage. On the other hand, theconstruction of the mechanism 110 in all other respects is substantiallyidentical with that of the mechanism 10. Thus, the latch mechanism 110includes a housing having a cover plate 112 coextensive with andcovering one face of a shaped casting 114, a stop plate 116 and machinescrews 117 holding the cover plate and stop plate fixed to the casting.Further, the casting includes segments 118, 120 and 122 which are formedwith the respective edges 124, 126, 137 and 138 to define the passagesI28 and 140 in which are received the slide 130 and release latch 142.The mechanism 110 also includes a toggle assembly 146 provided with thesame components and functioning in the same manner as the toggleassembly of mechanism except that the toggle assembly 146 is anchored inthe upper segment 122 being received in rounded groove 156 therein andengages with an upper edge of the release latch 142 in groove 158.Furthermore, the tongue extension 170 of the release latch 142 isprovided with a flat tongue surface 172 like that on release latch 42 ofmechanism 10. The mechanism 110 also is provided with a compressionspring 133 received in the blind bore 131 of the slide 130 for thepurpose of moving the slide following unlatching thereof.

The cam 134 of mechanism 110 as will be noted is different in itsprofile or plan shape than the cam 34 and has a relatively wide portionat one end including a convexly rounded end edge 165 formed complementalwith the curved portion 167 of recess 132 in slide 130. The cam has astraight longitudinal side edge 162, which at the other, narrow end 180of the cam rests against the surface 172 of the tongue extension 170 ofrelease latch 142. The recess 132 formed in the slide 130 is enlargedbut similarly shaped with respect to the cam profile so as to adapt itto receive the cam as the latter retracts during unlatching of themechanism. Segment 122 of casting 114 is provided at the corner thereofadjacent the intersection of passage 140 with passage 128 with a roundedfulcruming edge surface 135, and the other longitudinal side edge of thecam is provided with a complementally concavely rounded section 235which abuts with rounded edge 135 during fulcruming of the cam.

In operation, the mechanism 110 functions like mechanism 10 in thatrelease of the latching lever by a force F of low magnitude, will slidethe tongue extension 170 on the release 180, allowing the roundedsurface section 235 of the longitudinal edge 164 of the cam to abut withand fulcrum against fulcruming surface so that upward travel of theunlatched slide will rotate the cam clockwise moving it into the recess132 in the slide and completely retracting it from the release latchpassage to allow for unimpeded movement of the slide to its fullyunlatched position. The various positions the cam 134 has followingrelease of it from its holding position and during the movement of theslide 130 from retracted to unlatched position in the housing are shownin phantom lines in FIG. 6. Thus, it will be noted that as soon as thecam is released from its held position it starts to pivot clockwise andthe rounded surface 165 at the left end of the cam rolls against theconcave surface 167 of recess 132 until the slide reaches about midlength in its travel from latched to unlatched position, at which pointthe pivoting of the cam moves it against the side edge 126 of thepassage 128. In the latter condition, the cam is completely retractedwithin the recess 132.

It will be understood that in accordance with the present inventionvarious modifications can be made in the construction of the latchmechanism. For example, the housing need not comprise a casting 14.Rather, the segments 18, 20, 22 could be provided as separate items andassembled to a plate similar to the cover plate 12. Furthermore, thebiasing means employed to bias the release latch into latching positioncould be a type other than a toggle assembly. Other forms of biasingmeans could be employed.

It will thus be seen that the objects set forth above, among those madeapparent from the preceding description, are efficiently attained and,since certain changes may be made in the above construction withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

What is claimed is:

l. Latch mechanism comprising a housing having first and second passagestherein, said second passage intersecting said first passage to providecommunication therewith,

an elongated slide member received in said first passage for slidingstraight line travel therein, said slide member having a latchedposition in said first passage,

first biasing means engaging said slide member and tending to slide itin said first passage from said latched position,

an elongated release latch received in said second passage for straightline sliding travel therein, said slide member having a recess extendinglaterally inwardly therein from a side thereof, said recess registeringwith said second passage when said slide member is in said latchedposition,

an elongated cam, one end of said cam being receivable in said recess,the other end of said cam extending into said second passage, said latchrelease having a tongue extension at one end thereof, said tongueextension engaging the other end of said cam when said release latch isin latching position for holding said cam engaged in said recess andthereby prevent movement of said slide, and

second biasing means normally tending to slide said release latch in onedirection in said second passage and into its latching position,

a portion of said second passage adjacent its intersection with saidfirst passage being defined by a rounded fulcruming surface juxtaposedwith at least a portion of said cam when it is in its held position,

sliding movement of said release latch in an opposite directionreleasing said cam from its held position whereby unlatching of saidslide member is initiated,

the movement of said slide member from its latched position effectingfulcruming of said cam against said rounded fulcruming surface forretracting said cam into one of said slide recess and said secondpassage.

2. The latch mechanism set forth in claim 1 wherein said housingcomprises a plurality of shaped segments, each of said latch frombeneath the edge 162 of the cam at its narrow end 75 segments having atleast one side edge surface, said segments being arranged such that oneside edge surface of one segment lies opposed to and defines with a sideedge surface of another segment one of said first and second passages.

3. The latch mechanism set forth in claim 2 wherein said second passageextends fully transversely of said housing, said slide in its latchedposition being coextensive with said passage, said slide moving out ofsaid housing during movement from its latched position.

4. The latch mechanism set forth in claim 3 wherein housing is anelongated structure, said shaped segments being arranged such that saidfirst passage is disposed transversely in said housing and said secondpassage longitudinally in said housing.

5. The latch mechanism set forth in claim 2 wherein said second biasingmeans comprises a toggle assembly received in one of said segments forpivoting movement in a cavity formed in said one segment, said toggleassembly including a pair of longitudinally overlapping pins, and springmeans engaging said pins to urge them in opposite directions, theassembly at one end being pivoted in said cavity, the other end of saidassembly engaging said release latch.

6. The latch mechanism set forth in claim 1 wherein said first biasingmeans comprises a compression spring engaged at one end with said slideand at its other end with said housing.

7. The latch mechanism set forth in claim 6 wherein said slide has ablind bore extending longitudinally therein from one end of said slide,said compression spring being received in said blind bore, said housingfurther having a stop plate disposed across one end of said firstpassage, said compression spring engaging said stop plate.

8. The latch mechanism set forth in claim 1 wherein said cam has atleast one straight longitudinal side edge, the tongue extension of saidrelease latch having a flat surface, said other end of said cam beingsupported on said flat surface when said cam is held by said releaselatch in its latching position.

9. The latch mechanism set forth in claim 8 wherein the recess in saidslide has a straight section therein, the flat side edge of said cam atsaid one end being in abutment with said recess straight section whensaid cam is in held position.

10. The latch mechanism set forth in claim 9 wherein said roundedfulcruming surface is juxtaposed with said one flat longitudinal sideedge of said cam, said flat side edge abutting with said fulcrumingsurface during fulcruming of said cam, said cam retracting into saidsecond passage during movement of said slide from its latched position,the other side edge of said cam being rounded taper-ingly toward saidflat side edge in the direction of said one end of said cam tofacilitate movement of said cam out of said slide recess and into saidsecond passage.

11. The latch mechanism set forth in claim 8 wherein the recess in saidslide has a concavely curved section therein, said cam having a convexlycurved edge at said one end thereof, said convexly curved edge being inabutment with said recess concavely curved section when said cam is inheld position.

12. The latch mechanism set forth in claim 11 wherein said roundedfulcruming surface is juxtaposed with the other longitudinal side edgeof said cam, said other longitudinal cam side edge having acomplementally rounded portion therein, said rounded cam side edgeabutting with said fulcruming surface during fulcruming of said cam, therecess in said slide being similarly shaped in plan profile with theplan profile of said cam, said cam retracting into said slide recessduring movement of said slide from its latched position.

1. Latch mechanism comprising a housing having first and second passagestherein, said second passage intersecting said first passage to providecommunication therewith, an elongated slide member received in saidfirst passage for sliding straight line travel therein, said slidemember having a latched position in said first passage, first biasingmeans engaging said slide member and tending to slide it in said firstpassage from said latched position, an elongated release latch receivedin said second passage for straight line sliding travel therein, saidslide member having a recess extending laterally inwardly therein from aside thereof, said recess registering with said second passage when saidslide member is in said latched position, an elongated cam, one end ofsaid cam being receivable in said recess, the other end of said camextending into said second passage, said latch release having a tongueextension at one end thereof, said tongue extension engaging the otherend of said cam when said release latch is in latching position forholding said cam engaged in said recess and thereby prevent movement ofsaid slide, and second biasing means normally tending to slide saidrelease latch in one direction in said second passage and into itslatching position, a portion of said second passage adjacent itsintersection with said first passage being defined by a roundedfulcruming surface juxtaposed with at least a portion of said cam whenit is in its held position, sliding movement of said release latch in anopposite direction releasing said cam from its held position wherebyunlatching of said slide member is initiated, the movement of said slidemember from its latched position effecting fulcruming of said camagainst said rounded fulcruming surface for retracting said cam into oneof said slide recess and said second passage.
 2. The latch mechanism setforth in claim 1 wherein said housing comprises a plurality of shapedsegments, each of said segments having at least one side edge surface,said segments being arranged such that one side edge surface of onesegment lies opposed to and defines with a side edge surface of anothersegment one of said first and second passages.
 3. The latch mechanismset forth in claim 2 wherein said second passage extends fullytransversely of said housing, said slide in its latched position beingcoextensive with said passage, said slide moving out of said housingduring movement from its latched position.
 4. The latch mechanism setforth in claim 3 wherein housing is an elongated structure, said shapedsegments being arranged such that said first passage is disposedtransversely in said housing and said second passage longitudinally insaid housing.
 5. The latch mechanism set forth in claim 2 wherein saidsecond biasing means comprises a toggle assembly received in one of saidsegments for pivoting movement in a cavity formed in said one segment,said toggle assembly including a pair of longitudinally overlappingpins, and spring means engaging said pins to urge them in oppositedirections, the assembly at one end being pivoted in said cavity, theother end of said assembly engaging said release latch.
 6. The latchmechanism set forth in claim 1 wherein said first biasing meanscomprises a compression spring engaged at one end with said slide and atits other end with said housing.
 7. The latch mechanism set forth inclaim 6 wherein said slide has a blind bore extending longitudinallytherein from one end of said slide, said compression spring beingreceived in said blind bore, said housing further having a stop platedisposed across one end of said first passage, said compression springengaging said stop plate.
 8. The latch mechanism set forth in claim 1wherein said cam hAs at least one straight longitudinal side edge, thetongue extension of said release latch having a flat surface, said otherend of said cam being supported on said flat surface when said cam isheld by said release latch in its latching position.
 9. The latchmechanism set forth in claim 8 wherein the recess in said slide has astraight section therein, the flat side edge of said cam at said one endbeing in abutment with said recess straight section when said cam is inheld position.
 10. The latch mechanism set forth in claim 9 wherein saidrounded fulcruming surface is juxtaposed with said one flat longitudinalside edge of said cam, said flat side edge abutting with said fulcrumingsurface during fulcruming of said cam, said cam retracting into saidsecond passage during movement of said slide from its latched position,the other side edge of said cam being rounded taperingly toward saidflat side edge in the direction of said one end of said cam tofacilitate movement of said cam out of said slide recess and into saidsecond passage.
 11. The latch mechanism set forth in claim 8 wherein therecess in said slide has a concavely curved section therein, said camhaving a convexly curved edge at said one end thereof, said convexlycurved edge being in abutment with said recess concavely curved sectionwhen said cam is in held position.
 12. The latch mechanism set forth inclaim 11 wherein said rounded fulcruming surface is juxtaposed with theother longitudinal side edge of said cam, said other longitudinal camside edge having a complementally rounded portion therein, said roundedcam side edge abutting with said fulcruming surface during fulcruming ofsaid cam, the recess in said slide being similarly shaped in planprofile with the plan profile of said cam, said cam retracting into saidslide recess during movement of said slide from its latched position.